1. Field of the Invention
The invention relates to a food steaming device, more particularly to a food steaming device that has a heater and a water container that are separable from each other.
2. Description of the Related Art
Referring to FIG. 1, a currently available food steaming device has a heater 1 formed with a water receiving space 10. A cylindrical hollow protrusion 11 projects upwardly from the center of the space 10. During use, water is supplied into the space 10, and then a liquid collecting unit 12, one or more steaming trays 13 (only one is shown), and a cover 14 are stacked on the heater 1. Each of the steaming trays 13 is formed with a plurality of steam holes 130 in a bottom portion thereof.
When the heater 1 is activated, water in the space 10 is heated by the hollow protrusion 11 so as to generate steam. Steam is sent upward through a central hole in the liquid collecting unit 12 and the steam holes 130 in each steaming tray 13 so as to cook the food in the respective steaming trays 13 by a steaming operation. The drawback to this kind of food steaming device is that the water receiving space 10 is formed directly in the heater 1. To clean the space 10, therefore, the heater 1 itself has to be cleaned. Because the heater 1 has electrical wires and electronic components therein, these elements may become rusted, or more serious problems may occur, such as the short circuiting of the electronic components and the user receiving an electric shock. Hence, the food steaming device with such a configuration is not safe to use.
Referring to FIG. 2, the aforementioned food steaming device may be further provided with a quick steam producing unit 21 mounted on the hollow protrusion 11. The quick steam producing unit 21 quickens the pace of which steam is produced. The quick steam producing unit 21 is a sleeve having a single layer tubular wall 210 formed with a water inlet 211 at a bottom periphery thereof and surrounding an outer periphery of the hollow protrusion 11. The tubular wall 210 and a peripheral wall 110 of the hollow protrusion 11 define therebetween a small space which confines a small amount of water therein that is isolated from the remainder of the water in the water receiving space 10. When the hollow protrusion 11 is heated, the water confined in the small space between the tubular wall 210 and the peripheral wall 110 of the hollow protrusion 11 is heated first, and then the water in the water receiving space 10 gradually enters said small space through the water inlet 211. Steam is thus produced quickly.
However, the single layer tubular wall 210 of the quick steam producing unit 21 is unable to thermally isolate the water inside said small space from the low temperature water outside said small space. As a result, the low temperature water surrounding the tubular wall 210 reduces the temperature of the tubular wall 210 so that a limited amount of the steam is produced by the quick steam producing unit 21.